Mobile communication can be provided by different types of wireless networks, such as cellular networks and wireless local area networks (WLANS).
In dual-mode mobile devices, it may be advantageous to make use of a WLAN when available, and be able to switch to a cellular network when the WLAN is no longer available.
There remains a need for mechanisms for transferring an ongoing communication session (e.g. a voice call) on a dual-mode mobile device from an AP in a WLAN to a BTS in a cellular network (or vice-versa).